New phenylbenzazoles

ABSTRACT

946,728. Leather. CIBA Ltd. Sept. 14, 1960 [Sept. 23, 1959 ; Dec. 8, 1959], No. 19727/62. Divided out of 941,990. Heading C6C. [Also in Divisions A2, A5, B5, C2, C3, C4, C5, Dl, D2 and G2] Materials are protected against ultra-violet rays by means of compounds of formula where A1 is a branched alkyl group having at least 4 carbon atoms, A2 is an unbranched alkyl group, and n is I or 2 (see Division C2). Materials specified include fibrous materials such as skins and hides and leathers made from the latter and products made therefrom.

The present invention provides new phenylbenzazoles which, like, for example, the compound of the formula O -OH3 (1 are substituted by at least one branched alkyl group.

For the purpose of the present invention the term 2- phenylbenzazoles includes 2-pheny-lbenzoxazoles, 2-phenyl-benzthiazoles and Z-phenylbenzimidazoles. The new phenyl-benzazoles containing at least one branched alkyl group are suitable for use as agents affording protection from ultra-violet rays, more especially to the skin.

The products of the present invention contain at least one branched alkyl group which may contain one or several branchings and 3, up to for example 12, carbon atoms. When the molecule of the phenylbenzazole contains only one branched alkyl group, the latter may be bound either to the phenyl radical in position 2 or to the benzene radical condensed with the azole ring. Azole compounds containing 2 branched alkyl groups may contain, for example, one of them in the phenyl radical and the other in the benzene radical condensed with the azole ring. The branching may be in any desired position of the alkyl radical. In general it is of advantage when the branching begins immediately with the carbon atom of the alkyl group bound to the benzene nucleus so that it is either secondary [CH a1kyl) or preferably tertiary [-C(alkyl) In the simplest case the alkyl radical is an isopropyl group [CH(CH As further branched radicals may be mentioned, for example, isobutyl or isoamyl radicals, the branched octyl radical of the formula and more especially the tertiary butyl radical of the formula It is found particularly advantageous when the 2-phenylazole compounds contain in addition to one or if desired more than one branched alkyl radical as further substituents in the benzene nuclei at most only unbranched alkyl groups and/or chlorine atoms. As unbranched alkyl groups there may be mentioned above all the lower groups with 1 to 4 carbon atoms, more especially the methyl and ethyl groups. These azole compounds correspond to the formula in which R represents a benzene radical in which two vicinal cyclic carbon atoms are at the same time also members of the azole ring, R represents a benzene radical 3,95,422 Patented June 25, 1963 ice and X the complement to the azole ring, with the molecule containing as substituent at least one branched alkyl group and the benzene nuclei R and R contain as further substituents at most only unbranched alkyl groups and/ or chlorine atoms.

When the Zphenylbenzazole contains one or two branched alkyl groups and as further substituents in the benzene nuclei at most only two unbranched alkyl groups, it corresponds to the formula \C a) Ii -1 I l H X 0 I n in which A represents a branched alkyl group, A a lower unbranched alkyl group, X the complement to the azole ring and p=1 or 2.

In the above Formulae 2, 3 and 4 X represents the complement to the azole ring, that is to say in the case of the oxazoles an oxygen atom, in the case of the thiazoles a sulfur atom, and in the case of the imidazoles a nitrogen atom which has in addition to the two cyclic bonds also a bond to a hydrogen atom or to a substituent. The 2-phenyl-benzimidazoles correspond preferably to the formula in which R and R have the meanings shown above in connection with the Formula 2 and Y represents an alkyl group such as a methyl or ethyl group, or a hydroxyalkyl group such as a ,Bw-dihydroxypropyl or fi-hydroxypropyl group, or a benzyl radical, or preferably a hydrogen atom. When the cyclic nitrogen atom of the imidazole compound is substituted by a branched alkyl group, the molecule need not contain another such group.

The Z-phenylbenzazoles of the composition defined above are advantageously prepared in the following manner:

(A) From an acyl compound derived on one hand from a benzenecarboxylic acid and on the other hand from 'an ortho-aminohydroxybenzene, ortho-aminomer- 3 captolbenzene or ortho-diaminobenzene of which one amino group is primary and the other at most secondary, said acyl compound being substituted by at least one branched alkyl group, water is eliminated by heating and/or treatment with a water-eliminating agent, for example The acyl compounds required as starting materials for this reaction can be prepared by reacting an orthoaminohydroxybenzene, ortho-aminomercaptobenzene or ortho-diaminobenzene of the indicated type with a henzenecarboxylic acid halide, preferably an acid chloride, at least one of the two starting materials being substituted by a branched alkyl group. The elimination of water from the acyl compound can be accomplished, tor example, by simple heating, or more advantageously with the aid of a water-eliminating agent such as zinc chloride or boric acid.

(B) An acyl compound derived on one hand from a benzene carboxylic acid and on the other hand from an ortho-nitrohydroxybenzene, ortho-nitromercaptobenzene o-r 'ortho-nitroaminobenzene containing an amino group which is at most secondary, which acyl compound contains at least one branched alkyl group, is treatedwith a water-eliminating reducing agent, for example at 90- 100 C. with tin and hydrochloric acid. The acyl compounds (esters, thioesters or amides) required as starting materials can be prepared from the nitro compounds of the specified kind and benzenecarboxylic acid halides.

(C) By heating an ortho aminohydroxybenzene, orthoaminomercaptobenzene or ortho diaminobenzene one amino group of which is primary andthe other at most secondary, together with a benzenecarboxylic acid or a suitable functional derivative thereof, for example an alkyl ester, preferably in the presence of a water-eliminating agent, at least one of the two starting materials being substituted by a branched alkyl group, for example This reaction may be carried out in the absence of a solvent or in the presence of a high-boiling organic solvent. Also in this case good results are achieved with boric acid which is a water-eliminating agent and acts as a catalyst. Further suitable for this purpose are orthophosphoric acid, pyrophosphoric acid and polyphosphoric acid.

(D) When it is desired to manufacture Z-phenylbenzimidazoles substituted at one of the imidazole nitrogen atoms by a branched alkyl group, method A, B or C may be employed, using as starting material a suitable l-aminoor 1-nitro-2-N-alkylbenzoylaminobenzene or l-amino-Z- alkylaminobenzene. Alternatively, a 2-phenylbenzimidazole containing an imidazole ring nitrogen atom bound to a hydrogen atom may be reacted with an alkylating agent containing a branched alkyl group, for example G- Q hydrogen halide This reaction is advantageously carried out in the presence of an acid acceptor.

For the aforementioned use of the azole compounds as screening agents for ultra-violet rays (light filters) .there are'three'possibilities which-may be utilized singly or in combination with one another:

(A) The light filter is incorporated in a substratumfor the purpose of protecting the latter from the attack by manufacture of the latter or subsequently by way of a suitable operation, for example by a fixation process similar to a dyeing process.

B) The light filter is incorporated in a substratum to protect one or several other substances incorporated in the substratum such, for example, as dyestuffs or assistants, and this may be accompanied by the'protection of the-substratum mentioned under A above.

(C) The light filter is incorporated in a filter layer for the purpose of protecting an underlying substratum or a substratum which is at some distance from the filter layer (-for example in a shop window) from the attack of the ultra-violet rays; the filter layer may be solid (a film, foil or dressing) or it may be semi-solid (a cream, oil or wax).

As materials that can be so protected there may be mentioned the following:

(a) Textile materials quite generally which may be in any desired form, for example in the form of fibers, filaments, yarns, woven or knitted fabrics or felt, and all products made therefrom. Such textile materials may consist of'na-tural materials of animal origin such as wool or silk, or of vegetableorigin such as cellulosic .materials of cotton hemp, flax, linen, jute'or ramie;

furthermore of semi-synthetic materials such as regenerated cellulose, for example rayon, viscose rayon, including spun rayon, or fully synthetic materials accessible by polymerization or copolymerization, for example polyacrylonitrile, or products obtained by polycondensation such as polyesters and above all polyarnides. In the case of semi-synthetic materials it is of advantage to add the light filter to the spinning solution, for example a viscose spinning solution, acetyl cellulose (including cellulose triacetate) spinning composition; in the case of masses destined for the manufacture of fully synthetic fibers, such :as polyamide melts or polyacrylonitrile spinning compositions, it is of advantage to incorporate the light filter before, during or after the polycondensation or polymerization respectively.

(b) Fibrous materials of a different nature, not being textile materials, which may be of animal origin such as feathers, hairs, skins and hides and leathers made from the latter by natural or chemical tanning, as well as products made therefrom; or they may be of vegetable origin such as straw, wood, Wood pulp or materials made from densified fibers such as paper, cardboard or hardboard, as well as materials made therefrom; furthermore paper pulp (for example hollander pulp) used for the manufacture of paper.

(0) Coating and dressing materials for textiles and papers, for example those based on starch or casein or on synthetic resins, for example of vinyl acetate or derivatives of acrylic acid.

(d) Lacquers and films of various compositions, for example consisting of acetyl cellulose, cellulose propio nate, cellulose butyrate and cellulose mixtures such, for example, as cellulose acetate-butyrate and cellulose acetate-propionate; also nitrocellulose, vinyl acetate, polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, alkyl resins, polyethylene, polyamides, polyacrylonitrile and polyesters. The azole compounds are of special importance for incorporation in wrapping materials, more especially in the known transparent foils of regenerated cellulose (viscose) or acetyl cellulose. In this case it is as a rule of advantage to add the light filter to the mass from which such foils are manufactured.

(e) Natural or synthetic resins, for example epoxy resins, polyester resins, vinyl resins, polystyrene resins, alkyl resins, aldehyde resins such as condensation products of formaldehyde With phenol, urea or melamine; as Well as emulsions of synthetic resins (for example oil-in- Water or water-in-oil emulsions). In this case the light filter is advantageously applied before or during the polymerization or polycondensation respectively. Mention may also be made of synthetic resins reinforced with glass fibers and laminates made therefrom.

(f) Hydrophobic substances containing oils, fats or waxes such as candles, floor polishes, floor stains or other wood stains, furniture polishes, more especially those to be used for treating pale-colored, if desired bleached, wood surfaces.

(g) Natural rubber-like materials such as rubber, balata, gutta percha or synthetic vulcanizable materials such as polychloroprene, olefinic polysulfides, polybutadiene or copolymers of butadiene and styrene (for example Buna S) or butadiene and acrylonitrile (for example Buna N), which may additionally contain fillers, pigments, vulcanization accelerators and other assistants and in which the addition of the azole compounds of the invention is intended to delay the ageing and the attendant deterioration of the plasticity properties and embrittlement.

(h) For the manufacture of filter layers for photographic purposes, more especially for use in color photography.

It will be readily understood that the light filters are suitable not only for use with undyed but also with dyed or pigmented materials. In this case the protection extends also to the dyestuffs so that in some cases a very substantial improvement of the fastness to light is 6 achieved. If desired, the treatment with the light filter may be combined with the dyeing or pigmenting operation.

Depending on the type of material to be treated, on the demands made on the efficiency and stability and on other factors, the amount of light filter to be incorporated in the material concerned may vary within relatively wide limits, for example from about 0.01 to 10%, preferably from 0.1 to 2%, of the material that is to be protected directly from the ultra-violet rays.

As mentioned above, the phenylbenzazoles are particularly suitable for protecting the skin from ultra-violet rays. They can be made up in the usual manner into stable cosmetics ready for application. Advantageously, they are mixed, emulsified or preferably dissolved in a suitable vehicle. Such a vehicle may be liquid or semisolid. Relevant compounds are liquid organic diluents, for example organic solvents such as alcohols and ketones, for example ethanol, isopropanol, glycerol, cyclohexanol, methylcyclohexanol; furthermore trichloroethylene, petroleum products, esters of vegetable or animal origin such as vegetable or animal oils and fats, for example groundnut oil, cocoa butter and lanolin. Further suitable are mineral solvents such as paraffin oil, white mineral oil, or white petroleum jelly. When it is desired to produce an aqueous dispersion of the light filter, the latter can be finely dispersed directly in water with the aid of a suitable dispersant or completely or partially dissolved in one of the aforementioned organic vehicles and then dispersed or emulsified in water. It goes without saying that such mixtures and preparations may also contain further substances, for example skin creams, insect repellants, deodorants, aromatic substances and dyestuffs. By suitably selecting one or several vehicles and, if desired, incorporating further additives there are obtained solutions, ointments, pastes, creams, oils or emulsions.

With the aid of suitable solvents, for example fiuoro chloroalkanes, it is possible to make aerosol sprays which are kept in closed containers (dispensers) and can be applied from such containers to the skin area to be protected by actuating a valve.

The Z-phenylbenzazoles to be used as protective agents according to the present invention are particularly suitable for use as skin protectives because, on one hand, they are readily soluble in such organic solvents as are used for cosmetic purposes and, on the other hand, they absorb extensively ultra-violet rays of a wavelength up to about 320 m which redden the skin, While they have no influence on rays of a higher wavelength (320 to about 400 m which tan the skin, as is generally desirable.

Unless otherwise indicated, parts and percentages in the following examples are by weight. The ultraviolet absorption spectra have been determined in alcohol.

Example 1 35 .6 parts of para-tertiary butylbenzoic acid, 21.6 parts of 1:2-diaminobenzene and 0.6 part of boric acid are stirred under nitrogen for 2 hours at 205-21 O C., and the water formed is continuously distilled oil. The melt is cooled to C. and 2 00 parts of dimethyl formamide are added dropwise, whereupon a dark brown solution is formed.

The mixture is treated with water, whereupon the product of the Formula 1 precipitates in the form of palebrown crystals. Yield: 40 to 45 parts. The analytically pure product obtained by two recrystallizations from aqueous alcohol melts at 249.5 to 250 C. and displays the following analytical data:

C H N .-Calculated: C, 81.56%; H, 7.25%; N,

11.19%. Found: C, 81.44%; H, 7.33%; N, 11.22%. k =305 m (e=2l200). The product can be used as a substance aifording protection from ultra-violet rays, more especially as a skin protective. Other compounds, shown in the following table, can be produced in the manner described above and used for the indicated purpose.

.tective from ultra-violet rays.

Analysis No. Formula Melting 'Max point, 0.

' Calculated Found H3C\ N 1 81.24 ;H 0.82 81.00 ;H 7.027- =307 mp (9)m H3O Q CH8 7H5 'N, 57 N,5.5 7 2:29,

(ll/Ha N HaC-C (3H3 (10).... 0 0-0113 157-157.5 0, 82.04%; H, 8.20%; 0, 82.10%; H, 8.21%; imux=sos my,

3 I N, 4.50%. N, 4.86%. =24,

\O/ CH on J 1 C- CCH: 106.8-107.2 ,0, 76.36%; H, 6.41%; c, 76.65%; H, 6.47%; lunar-302 mg,

g ,5.24%. N, 5.00%. e= \S/ H:

N 01 F 12)-.-- 0 0-011, 155.4-157 0, 71.45%; 115.64%; 0, 72.01%; H, 5.74%; max=308 my,

\ I N,.4.00%. N, 4.93%. $31,400.

7 7 N mo-o-om-o (13)... E CH3 /0-0H3 112. 5413.5 0. 5223 H,"8.47%; 0, 82.21%; H, 8.63%; Amu=308 mu,

Example 2 lizations from aqueous alcohol, melts at 113-1135 C.

When in Example 1 1:2-diaminobenzene is replaced by an equivalent amount of l-hydroxy-Z-aminobenzene there is obtained the product of the formula Example 3 8.3 parts of 1-hydroxy-2-amino-4-tertiary butylbenzene,

"6.3 parts of 4-methylbenzoic acid and 0.2 part of boric acid are maintained under nitrogen for 2 hours at 200- .210" C., the water formed being continuously distilled off. The temperature is. allowed to drop to 150, 50 parts of dimethyl formamide are added and the darkbrown solution is treated with parts of water, whereupon the product of the formula (15) g /N\ precipitates in yellow crystals; it can be used as a pro- Yield: about 12 parts. The analytically pure product, obtained by four recrystaland displays the following analytical data:

C H ON-Calculated: C, 81.52%; H, 7.17%; N, Found: C, 81.47%; H, 7.22%; N, 5.28%. i =307 Inp. 28400).

.of adipic acid isopropyl tetrahydrofurfuryl ester and 1 part of glycerol monostearate are dissolved in 84 parts of ethanol. The solution affords protection from sunrays and repels insects and isvexcellently suitable for rubbing into exposed parts of thebody.

Instead of the compound of the Formula 1, one of the compounds (9) to (15) can be used with asimilar Example 5 A solution of 4 parts of the compound of the Formula 1' in 96 parts of ethanol is treated with 0.5 part of essential oils. 40 parts of the resulting solution, together with 60 partsof a mixture of equal parts of trichloromono- Example 6 10 parts of adipic acid ,isopropyl tetrahydrofurfuryl ester, 5 parts of benzoic acid diethylamide, 8 parts of phthalic acid, dimethyl ester and '5 parts of one. of the compounds of the Formulae 1 or 9 to 15 are dissolved m a mixture of 3 6 parts of groundnut oil and 36 parts ofparafiin oil. The resulting product isa sunburn preparation which also repels insects.

Example 7 An intimate mixture is prepared from 4 parts of one of the compounds of the Formulae 1 or 9 to 15, 10 parts of glycerol monostearate, 4 parts of cetyl alcohol, 1 part of sodium cetyl sulfate, 1 part of stearic acid and 5 parts of glycerol and emulsified in 75 parts of water.

The resulting emulsion is a very efficient non-greasy skin cream and protects the skin treated with it from sunburn.

Example 8 An intimate mixture is prepared from 5 parts of adipic acid isopropyl tetrahydrofurfuryl ester, 5 parts of toluylic acid diethylamide, 3 parts of one of the compounds of the Formulae 1 or 9 to 15, 6 parts of cetyl alcohol, 14 parts of paraffin oil, 10 parts of white beeswax, 14 parts of lanoline, 3 parts of cocoa butter, 39.7 parts of water and 0.3 part of sodium benzoate. The resulting cream protects the skin from sunburn and repels insects.

Example 9 A film of a thickness of about 40 is prepared from a solution in acetone of 10% strength of acetyl cellulose containing 1% of the compound of the Formula 14 calculated on acetyl cellulose. After having been dried, part of the resulting film is exposed for 100 hours in a fadeometer. The following values of permeability in percent are found:

Permeability to light in percent Wavelength in m Exposed Unexposed V 70 340 to 400 90 Example 10 Para-hydroxybenzoic acid methyl ester 0.3 Distilled water 51.9

The oil phase A is melted, heated to 70 C. and vigorously stirred into the aqueous phase B which is heated at 75 C. The emulsion is rinsed cold and perfumed (0.3 part of perfume).

10 Example 1 1 A solution is prepared in the usual manner from Parts Compound of one of the Formulae 1 or 9 to 15 3 Polyethylene glycol, molecular weight 300 40 Propylene glycol 25 Isopropyl myrist 2.5 Ethanol 29.2 Perfume 0.3

This solution protects the skin from ultra-violet rays. It is advantageously applied to the skin with the aid of a suitable sprayer.

What is claimed is:

l. The 2-phenylbenzoxazole of the formula 2. The 2-phenylbenzoxazole of the formula C iZH. a.

3. The Z-phenylbenzoxazole of the formula C CH.

4. The 2-phenylbenzoxazole of the formula it... (l

5. The 2-phenylbenzoxazole of the formula References Cited in the file of this patent UNITED STATES PATENTS Hao moi;

2,746,971 DoIton May 22, 1956 2,932,649 Metivier Apr. 12, 1960 2,933,503 Clark et a1 Apr. 19, 1960 2,985,661 Hein et a1 May 23, 1961 OTHER REFERENCES Ierchel et al., Chem. Abstracts, volume 47, column 2752-3 (1953). 

1. THE 2-PHENYLBENZOZAZOLE OF THE FORMULA
 2. THE 2-PHENYLBENZOXAZOLE OF THE FORMULA
 3. THE 2-PHENYLBENZOXAZOLE OF THE FORMULA
 4. THE 2-PHENYLBENZOXAZOLE OF THE FORMULA
 5. THE 2-PHENYLBENZOXAZOLE OF THE FORMULA 